Underwater vehicles are typically controlled using actuated fins that protrude from the vehicle into the flow field around the hull. If the fins on the vehicle come into contact with a foreign object moving with a different velocity than the vehicle, the inertia of the vehicle can cause extremely high forces to develop on the fin, coupling, and actuation system. In order to prevent transmission of these forces into the structure of the vehicle and limit damage to the actuators driving the fins, there exists a need for a force limiting coupler between the actuation system and the fin.
Furthermore, the hull of an underwater vehicle is typically designed and manufactured in separate sections. The separate hull sections typically are joined by metal rings that are bonded to the hull by adhesives or fasteners. However, hull sections made out of composite materials generally cannot accommodate sharp angles as well as metal, making it difficult to use trapezoidal cross section band clamps typically used on torpedoes. Moreover, since underwater vehicles are generally engineered to be similar in density to water, any saved weight can translate to greater buoyancy, greater payload volume, and lower manufacturing and operating costs. Thus, these hull interfaces present an opportunity to design a robust underwater vehicle with a joint geometry that is light, low cost, strong, and relatively rigid.
Forward looking sonar arrays also present an opportunity to increase robustness of underwater vehicles. Most forward looking sonars are precariously placed in the front of a vehicle and are often destroyed in the event of a collision. Furthermore, a front-mounted sonar array typically results in a planar-shaped bow section, which may expose the sonar to damage. Moreover, the hydrodynamics of the vehicle are often disrupted due to the planar bow shape and the constraints of the sonar (planar boxes to accommodate planar arrays, etc). Thus, there exists a need to design a robust underwater vehicle with improved protection for forward-facing sonar arrays.